Battery
About History Allensanaro Volta is the man that gave us the word volt, our unit for electrical pressure of electromotive force. In 1789 he took a copper rod and a zinc rod and immersed them both in an acetic acid solution. He had just constructed the first battery cell with the first electrolyte. The copper and zinc rods were the electrodes, positive and negative. The acid started to eat away the zinc rod, while the copper rod captured the energy released from the action. A voltage developed between the two electrodes. Volta had invented the battery. The electrochemical principles that he discovered are still the foundation for the battery industry. Seventy-nine years went by before George Leclanch developed a practical cell. He used manganese-dioxide powder as the positive electrode instead of copper; he kept the zinc. He used sal ammoniac (ammonium chloride) in water for his electrolyte. A porous cup held the powder which surrounded a carbon collector. Leclanch put the whole business, or the cell, into a glass jar and invented the first wet battery. The first dry cell battery was manufactured in 1888 under the auspices of a Dr. Gassner. It was to become the prototype for the dry cell battery industry. Gassner used zinc to hold all of the components and kept zinc for the negative electrode as well. The electrolyte material was absorbed by a porous medium. He also added zinc chloride to the electrolyte, which cut back zinc corrosion when the cell was inactive. This was a big step for longer battery storage life. Now, for the first time a dry cell battery was a neat, tightly sealed package, almost ready for mass production. It didn't take long. Batteries were first mass-produced in 1890 by the National Carbon Company at their plant in Cleveland, Ohio. Later they became the industrial giant known as Union Carbide. Between 1890 and the 1970's, dry cell batteries increased in popularity, but there were no significant changes in design. During the 1970's, battery technology began increasing rapidly, with new batteries and new ways of making the old batteries occurring regularly. Primary vs. Secondary Primary batteries are used once, then discarded. They have the advantage of convenience and cost less per battery, with the down side of costing more over the long term. Generally, primary batteries have a higher capacity and initial voltage, and a sloping discharge curve. Primary batteries do not presently require special disposal. Primary batteries *Carbon Zinc *Zinc Chloride *Alkaline Batteries *Standard Alkaline *Premium Alkaline *Lithium Manganese *Zinc Air *Silver Oxide *Mercuric Oxide Secondary batteries are the rechargeable batteries. They have the advantage of being more cost-efficient over the long term, although individual batteries are more expensive. Generally, secondary batteries have a lower capacity and initial voltage, a flat discharge curve, and varying recharge life ratings. Ni-Cd and small-size lead acid batteries require special disposal and should not be simply thrown away. Secondary batteries *Nickel Cadmium *Nickel Metal-Hydride *Lithium Ion *Lithium Ion Polymer *Lead Acid Recommended Temperature Usage Not all batteries are recommended for all temperature extremes; choose a battery which matches your environment. Recommended Devices Because different batteries are recommended for different device types, you should choose a battery which matches your type. High Discharge Rate Devices can be loosely defined as those with current consumption of 600 mA or higher. Low to Moderate Discharge Rate Devices can be loosely defined as those with current consumption of less than 600 mA. Storage Batteries will self-discharge over time. If you will be using the battery intermittently, you would want a battery with a longer storage life. Storage is an indicator of how long the battery will last before self-discharge renders the battery dead. Generally, there will be a date code on the battery or packaging such as 1A2. This code indicates that the battery was packaged in January of 2002. Batteries should not be stored in the device if the device is not being used. Leaving batteries in a battery compartment for long periods (a week or longer) can cause the batteries to leak. Two or three days should not be a problem; however, if the device will be unused for a week or longer, we recommend that the batteries be removed. Other factors to consider when choosing a battery include initial voltage, capacity, the discharge curve, recharge life (for secondary batteries) and disposal requirements. The Technical Information section has a Battery Comparison Table which allows you to quickly compare these ratings. Initial Voltage This is the voltage when the battery is new and fully charged. Devices will often use the voltage as the indicator for battery life. When it drops below a given point, the battery is considered dead. A higher initial voltage generally indicates longer battery life. For primary cylindrical batteries and rechargeable alkalines, the initial voltage is 1.5 volts. For the other secondary batteries, the initial voltage is between 1.2 and 1.25 volts. Capacity In rechargeable batteries, capacity is listed as ### mAh (or ## Ah); this information allows you to estimate battery life in a device with known current drain. In alkaline batteries, the sloping discharge curve makes it impossible to accurately provide a mAh rating; the rating would vary depending on discharge rate and temperature. Discharge Curve: Flat or Sloping The discharge curve is plotted as voltage against time, at a given current drain and temperature. A flat curve indicates that the battery discharge rate is steady until it is nearly discharged. A sloping curve indicates that the discharge rate changes over time. Generally speaking, primary batteries have sloping discharge curves and secondary batteries have flat curves. Battery Shelf Life There are three types of battery life to consider -- how long it lasts just sitting there (shelf life), how long it lasts powering a particular device (use life), and how many times it can be recharged (recharge life). Shelf life varies depending on battery type and temperature; however, there should be a date code ('03-01' or '07-02') printed on the battery’s package. This code indicates the use before date. Older batteries may have a date code in the format '1A8', which indicates the manufacturing date (in this case, 1 = January and 8 = 1998). * Batteries should be stored at 40-50 degrees F. Batteries should not be stored in the freezer or in very hot environments (such as a car's glove box). * Batteries stored at a temperature above 125 degrees F will deteriorate particularly quickly. * Zinc-Air batteries are the only type of batteries that we sell that do not begin discharging until you begin to use them. A zinc-air battery has a tab (usually plastic) that must be taken off before you use it. It begins to discharge when the tab is removed. Use life (or how long a battery will last in a given device) depends on the current drain of the device and the capacity (mAh) rating of the battery. The basic formula is given below: Capacity (divided by) Current Drain (multiplied by) 0.7 (equals) Approximate Battery Life The factor of 0.7 makes allowances for external factors which can affect battery life. The primary factor is temperature. * Batteries have different operating temperatures; see the Battery Comparison Chart for specific information. * Using a battery under extreme heat may cause it to produce more energy; however, its overall life is reduced. * Using a battery under cold conditions may cause it to produce less energy, and again, overall life is reduced. Recharge life is the number of times a rechargeable battery can be discharged and recharged (1 cycle) and still be effective. Over time, rechargeable batteries will lose their capacity for recharging. Testing batteries The most important thing to understand about testing batteries is that batteries will not show their correct voltage unless they are under a load. If you simply take a multimeter and connect the leads to each battery terminal, you will not get an accurate reading. Battery testers are designed to place the battery under a load in order to get an accurate reading and are best for normal consumer use; however, multimeters provide a more accurate reading of the voltage potential. If you are needing a high level of accuracy (such as for design or testing), then you should use a multimeter. If you are just wanting a device to let you plug in a battery and know whether or not it's still good, a battery tester is a better choice. Multimeter Battery Test When testing batteries with a multimeter, you must have the meter set to measure DC voltage and place the battery under load by using a resistor in parallel with the test leads of the meter. If the voltage reads the same on a multimeter with the resistor or without, then the battery is either low or dead and should be replaced. A battery can be used until it is down to about 30% capacity. After that, it typically will not supply enough voltage to power the product it is being used in. The actual cut-off voltage will vary with the battery type. The Memory Effect Originally, the terms memory effect or memory problem was coined to describe a cyclic memory problem where the Ni-Cd battery would remember the amount of discharge for previous discharges and limit the recharge life of the battery. In the most technical sense, this does not occur in modern Ni-Cd batteries, which are designed to avoid cyclic memory issues. The confusion began when, as battery technology advanced, the terms were also used to describe the problem of crystal growth (which causes similar symptoms). Crystal growth can occur when a modern Ni-Cd battery is recharged before it is fully discharged. The crystal growth can eventually prevent the battery from discharging beyond that point and/or cause rapid self-discharge of the battery. While there is an ongoing (and lively) argument as to whether or not the crystal growth issue is or is not a memory effect or memory problem, our concern is how to help our customers avoid or reverse the problem. You can avoid crystal growth in the battery by either completely discharging it each time it is used or by using a Ni-Cd battery charger which has a built-in discharge circuit. If you have a Ni-Cd battery which has already been repeatedly recharged without being fully discharged and/or a battery which will no longer take a full charge, you can sometimes reverse the crystal formation by putting the battery through several complete discharge and recharge cycles. The fastest method for doing this is to use a Ni-Cd battery charger with a built-in discharge circuit (as above). However, you can also do this by running the device with the battery installed until it completely dies, and then use a standard charger. Vendors *Alpha Source *Apex Battery *Battery Clinic *Odonnell Batteries *R and D Batteries *Unipower *PartsSource *High-Tech Battery Solutions Hazardous or Non-Hazardous The following matrix determines of few batteries that are considered hazardous and must be disposed of according to local and state law as well as the hopspital's Hazardous Waste Management Plan. Non-hazardous (alkaline) batteries can be simply discarded in the trash. If any doubt what batteries are hazardous consult the battery MSDS, OEM, or local safety officer. References Form DD 7473-R - BATTERY INSPECTION CHECKLIST Links Battery University Video thumb|300px|right See also * AA battery * AAA battery * AAAA battery * C battery * D battery * Alkaline battery * Battery holder * Battery Management System (BMS) * Battery pack * Battery recycling * Battery terminals * Car battery * Depth Of Discharge (DOD) * Galvanic cell * Electrochemical cell * Energy density * Energy storage * Lead-acid battery * List of battery sizes * List of battery types * PP3 battery, also known as "9-volt" * Rechargeable battery * State Of Charge (SOC) * State Of Health (SOH) * Trickle charging * Watch battery Category:Electronics Category:Batteries Category:CBET Study Info Category:Components